2.2.1 Common Definitions

Except where noted, the headers in this document are specified using the Augmented Backus-Naur Form (ABNF) grammar, as specified in [RFC4234] section 2.2. The following common constructions are used throughout this document.

These constructions are used solely for convenience in constructing other types and have no semantics in and of themselves.

 httpURL = 1*(ALPHA / DIGIT / ":" / "." / "\" / "/" / "%" / "_" / "&" / "?")

The following constructions are used in protocol header definitions:

 scheme = "Passport1.4"
 ExtraParams = *("," ptoken) ptoken
 challenge = ExtraParams
 OrgVerb = "OrgVerb=" ptoken 
 OrgURL = "OrgUrl=" httpURL
 tname = "tname=" ptoken
 from-PP = "from-PP=" ptoken
 ptoken   = 1*<any CHAR except CTLs or ",">
 ConfigVersion = "ConfigVersion=" 1*DIGIT

scheme: Identifier for the Passport SSI Version 1.4 Protocol authentication scheme.

ExtraParams: Additional parameters not interpreted by this protocol that MAY be used for vendor extensibility.

challenge: A comma-separated list of parameters returned by a server for use by a client in the process of proving its identity.

OrgVerb: A string containing the HTTP verb that triggered the original server challenge, for example, "GET".

OrgURL: The URL in an HTTP request that triggered a server challenge.

tname: An informational parameter that contains the name of a cookie specified on a response. A client SHOULD ignore this parameter.

ptoken: A string that can contain any alphanumeric characters and separators, except for a comma.

from-PP: A string that is opaque to the client. This value is received from a server and MUST be passed back unchanged on a subsequent request.<2>